Vortex spectrum of perturbed singular beam and informational Shannon entropy

We demonstrated transformations of vortex beams subjected to sector disturbances in the form of a diaphragm with hard edges. The transformations of the vortex spectra, the orbital angular momentum, and the informational entropy of the perturbed beam are studied. We found that relatively small angular perturbations of the sectors have almost no effect on the OAM, although the information entropy is rapidly increasing due to the birth of new optical vortices caused by diffraction at the edges of the diaphragm, while the information entropy sharply increases.